So my mom has a 40 year old hydrangea plant in her back yard. It hasn't bloomed in years, as I don't think it particularly likes it's spot in the sun, but it's too big to move. So, I decided to take some cuttings of the plant and propagate them in hopes of giving it a new lease on life.

I'm using the method described here: http://www.nantuckethydrangea.com/propagation.html

So my question is, once my numerous cuttings have rooted and are ready to be transplanted, how many of the little cuttings can I put in one pot? I am wanting to keep it potted for now, as we may move in the next year to two years and I would like to keep it mobile. So how many cuttings can I safely put in a 16" planter?

Thank you in advance!